Mechanical testing ,Tensile tests ,Toughness testing (Charpy, Izod) ,Macro testing ,Bend testing ,Fillet weld fracture testing

WHAT IS MECHANICAL TESTING ?

     ⦁ The ultimate means by which the mechanical strength and toughness of a prepared test object  can be determined by subjecting it to mechanical forces beyond the limits of its own mechanical  resistance.

Destructive testing of welded joints are usually carried out to:

     ⦁ Approve welding procedures
     ⦁ Approve welders
     ⦁ Production quality control

The following mechanical tests have units and are termed quantitative tests

     ⦁ Tensile tests : Tensile test is performed on welded test specimen as part of the weld procedure  (WPS / WPQR) qualification, welder qualification, weld performance qualification and Production weld qualification.

     ⦁ Toughness testing (Charpy, Izod) : Both Charpy and Izod impact testing are popular methods of determining impact strength, or toughness, of a material. In other words, these tests measure the total amount of energy that a material is able to absorb. This energy absorption is directly related to the brittleness of the material.

The following mechanical tests have no units and are termed qualitative tests

      ⦁Macro testing : Macro examination is the procedure in which a specimen is etched and evaluated macro-structurally at low magnifications, typically x10 or lower. Macro examination is a frequently used technique for evaluating steel products such as billets, bars, blooms, and forgings.

      ⦁Bend testing : The bend test is a simple and inexpensive qualitative test that can be used to evaluate both the ductility and soundness of a material. The bend test uses a coupon that is bent in three point bending to a specified angle.

      ⦁Fillet weld fracture testing :The fillet weld break test / fracture test  is a mechanical testing process for examining the root penetration in a destructive manner. While the macro-etch test provides penetration depth of the specimen in a given area, the fillet weld break test examines the root penetration for the entirety of the specimen. The test includes the potential failure points of the weld which are the stop and restart of the weld